Lectures 1-3 learning

• Organism-Environment System


  • Physiological factors
  • Other organisms
  • Natural forces
• Behaviour


  • Events/Stimuli
  • Behaviours and learning
• Reflexive behaviours


  • Eye-blinking, "sucking" and "gripping" in new-born humans
• Instinctual behaviours


  • Imprinting, homing, migratory behaviours
• Learning


  A relatively permanent change in behaviour or knowledge as a result of experience
• Learning types


  1. Habituation

  2. Classical Conditioning

  3. Instrumental conditioning

  4. Observational learning
• Habituation


  The decline in the tendency to respond to stimuli that have become familiar due to repeated exposure
• Classical Conditioning


  A neutral stimulus (NS) is repeatedly paired with a stimulus (US) that automatically elicits a particular response (UR). The previously neutral stimulus becomes a conditioned stimulus (CS) that also elicits a similar response (CR).
• Classical conditioning found in many species
• Human classical conditioning


  • US (puff of air) -> UR (eye-blink)

  NS (soft click) -> (no eye-blink)

  NS (click) + US (air) -> UR (eye blink)

  CS (click) -> CR (eye-blink)
• Applied issue: Bed wetting

  • Bladder feels full -> Child wets bed, keeps sleeping

  Vibrator activated -> Child wakes up

  Parents praise child
• Conditioned Emotional Responses


  Neutral stimuli (sounds, smells) associated with emotional events can elicit emotional responses
• Conditioned Fear


  • Children: "Little Albert" and J.B. Watson & Rosalie Raynor

  Adults: WWII veterans had changes in GSR to the sounds of battle even 15 years after the war
• Advertising


  • McBurger + Cute children -> "The warm fuzzies"

  Other advertisements create a mood
• Fetishes


  A person has heightened sexual arousal in the presence of certain inanimate objects
• Other examples: Allergic reactions, anticipatory nausea, immune responses
• Relation between the UR and the CR

  While UR and CR are often very similar, they are not necessarily identical
• Compensatory-Reaction Hypothesis


  Sometimes, the UR and the CR can be opposites
• Insulin injections


  • Bodily reactions to the various CS produce opposite response to the drug (i.e., blood sugar levels go up)
• Opiates (e.g., morphine, heroin)


  • Stimuli surrounding drug injections produce a compensatory reaction - depression, restlessness, increased sensitivity to pain
• The compensatory reaction requires CSs to elicit the physiological "preparedness" for the drug. What if the drug is administered without the compensatory reaction? The same dose might be lethal because the body is unprepared.
• Acquisition


  The process by which a conditioned stimulus comes to produce a conditioned response. i.e., how a NS becomes a CS.
• Factors affecting acquisition


  • Number of NS and US pairings

  US Intensity

  CS-US temporal relations
• CS-US temporal relations


  Delayed (Forward) Conditioning

  Trace (Forward) Conditioning

  Simultaneous Conditioning

  Backward Conditioning
• Effectiveness of CS-US temporal relations depends on the type of CR
• Contingency


  The relationship between the CS and the US
• Effective procedure for acquiring CR

  1. CS (click)

  2. US (air puff)

  3. Effective interval depends on the type of CR (Eye-blink 0.5 s)
• Trace (Forward) Conditioning


  1. CS (click) starts and finishes before the US

  2. Less effective than delayed conditioning
• Simultaneous Conditioning


  1. CS (click) and US (air puff) start and end together

  2. Often fails to produce a CR
• Backward Conditioning


  1. CS (click) begins after the US (air puff)

  2. Least effective way to acquire the CR (Can actually produce the opposite effect)
• Contingency


  • A simple contiguity between the US and CS is not sufficient for conditioning to occur
  • The CS must also be a reasonable predictor of the US
  • The strength of the conditioned response depends on how often the CS accompanies the US, and how often the CS accompanies no US
• Contingency example


  • 50 trials click + puff, 10 trials click alone - "click" should be a CS -> CR (eye-blink)
  • 50 trials click + puff, 100 trials click alone - unlikely "click" elicits a CR, because "click" is a poor predictor of "puff"
• Extinction


  1. If the CS is repeatedly presented without the US, then the CR will gradually decrease

  2. The rate of decrease depends on factors such as initial response strength
• Spontaneous Recovery


  1. A CS -> CR relation is extinguished

  2. After a period with no CS presentations, the CS may elicit the CR again

  3. Revived CR is less intense, re-extinguishes relatively quickly
• Flooding (Behaviour Therapy Application)


  • Fear elicited by a CS (certain phobias) is eliminated by process of extinction
  • Some therapists regard flooding as too stressful for the patient
  • Spontaneous recovery has obvious implications for therapies such as flooding
• Stimulus Generalisation


  A conditioned response formed to one conditioned stimulus will occur to other, similar stimuli
• Stimulus Discrimination


  Stimulus discrimination occurs when an organism does not respond to stimuli that are similar to the stimulus used in training
• Stimulus Generalisation example


  • "Little Albert" also feared a furry white rabbit, fur coat, Santa Claus mask
• Generalisation gradients


  • Continuous stimulus dimensions can produce generalisation gradients
  • Stimuli closer the CS, produce greater CRs
• Discrimination training


  • Stimulus A is associated with the US, and Stimulus B is not
  • If the subject discriminates, the CR occurs only with A